Co-pending patent application WO 95/05169 (Strathclyde University) relates to flavonoids and their use in methods of treating anxiety in patients. The flavonoids of WO 95/05169 are described as having anxiolytic properties without associated depression of the central nervous system (e.g. sedative and muscle relaxant effects) commonly found with benzodiazepines. The compounds of WO 95/05169 fall under a general formula: ##STR2## wherein
R.sup.1, R.sup.2, R.sup.3 and R.sup.4, R.sup.5 and R.sup.8 are independently selected from H, OH, R, NO.sub.2, halo, OR, NH.sub.2, NHR, NR.sub.2, COOR, COOH, CN, or a sugar group;
R.sup.6 and R.sup.7 are both H, or R.sup.6 and R.sup.7 together form a single bond;
R is C.sub.1-6 alkyl or alkenyl; or dimers thereof.
Preferred compounds of WO 95/05169 are described in halo derivatives, in particular where R.sup.5 is halo at the 2' position of the above general formula.
It has now been found that certain compounds falling within the generic formula of WO 95/05169 exhibit unexpectedly good anxiolytic activity without associated depression of the central nervous system (e.g. sedative and muscle relaxant effects) commonly found with benzodiazepines, when the flavone nucleus and/or phenyl ring comprises at least one NO.sub.2 substituent. Thus, patients may be treated for anxiety without inducing sedative or myorelaxant side-effects.
It has also been found that compounds of the present invention display a substantially reduced or no anti-convulsant effect, and that memory is apparently not adversely affected, side-effects commonly found with benzodiazepines.